1. Field of the Invention
The present invention relates to wireless communication and, more particularly, to a method of receiving downlink data using the allocation of downlink power in a wireless communication system and a wireless device using the same.
2. Related Art
3rd generation partnership project (3GPP) Long Term Evolution (LTE), that is, an improvement of a Universal Mobile Telecommunication System (UMTS), is introduced as the 3GPP release 8. The 3GPP LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in downlink, and uses Single Carrier-Frequency Division Multiple Access (SC-FDMA) in uplink. The 3GPP LTE employs Multiple Input Multiple Output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-Advanced (LTE-A) that is an evolution of the 3GPP LTE.
As disclosed in 3GPP TS 36.211 V8.7.0 (May 2009) “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 8),” in 3GPP LTE/LTE-A, physical channels may be divided into a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH), that is, downlink channels, and a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH), that is, uplink channels.
The allocation of downlink power is one of major factors for securing the communication reliability of downlink data. A BS determines the transmission power of a reference signal and the transmission power of a data channel and sends downlink data on the reference signal and the data channel. UE determines the transmission power of a data channel based on the transmission power of the reference signal received from the BS.
The transmission power of the reference signal is basic information used to determine the transmission power of the data channel. As reference signals for various uses are introduce, there is a need for a method for determining the transmission power of a reference signal.